Generally, the body and frame of a baby bed are made of tubular material such as round steel pipes or square pipes. It is, however, rather difficult to account for all relevant criteria in making the body and frame of a folding bed. Indeed, the load capacity or strength of the bed must be considered and the possibility of unintentional folding during use must be guarded against. Such considerations are essential in designing folding mechanisms. Meanwhile only conventional small baby carriages fulfill such essentials; baby beds which are for sleeping and playing therein have not met such essential requirements. In this regard it must be recognized that a small baby carriage does not require extensive or multiple folding operations because it is small in size. Consequently, the volume under consideration before or after folding is not very much. Contrariwise, a large baby bed always has to be folded in order to reduce space for its storage.